Toggle press guard



Sept. l, 1931.

TOGGLE PRESS GUARD Filed May 3 1929 2 Sheets-Sheet l @www A TTORNEYS.

Sept. l, 1931. F KUNKEL 1,821,651

ToGGLE PRESS GUARD Filed May 3, 1929 2 Sheets-Sheet 2 ff Fig. 4.

IN VEN TOR.

wav W@ MMM w ATTORNEYS.

Patented Sept. 1, 1931 UNITED :STATES PAT FREDERIC; H; KUNKEL, on MILWAUKEE f'wIscoNsIN, AssIeNoR 'ro entren, p

-rAnscHxn-a naar COMPANY, or MiLWAUKnE,wisconsin lA CORPORATION 0F WISCONSIN TOGGLE PRESS GUARD Applicationjled May Y3, 1

This inventionrelates toa'safety device for use on pressesand more particularly to a safety device in the form of a traveling gate operating in synchronism with; the mech anis'm of, a toggle :punchypress, and acting to insure that the person feeding the press removes his hand from beneath the blank holder and'punch before the blankholder or punch descends into proximity to the die. One ofthe'principalf objects of the present invention is to 'providea safety guard or safety device of this character which insures that the feeder removes his handY from beneath the blank holder and punch in ample time to avoid any possibility of his hand being caught and crushedzor. otherwise injured, the safety device operating in advance of the movement of theblank holder and punch in effecting this purpose.. f vAnother object of the invention is to provide a safety device of this character and having these advantages and which is of simple .and durable construction, reliable .and effective in operation, easy and comparatively inexpensive to manufacture and adapted to be installed on standard presses without modilication of the press construction and without interfering'with its operation or with the changing of the tools or dies..y Othen objects andy advantages reside in certain novel,` features of the construction, arrangement and combination of parts which will be hereinafter'more fully `described and particularly pointed out inv the appended claims,'reference being had to the accompanying drawings, forming -a part of this specificati0n,"and in -`which: 'f f Figure 1 isa view infront elevation showing a conventional typeKY of press'equipped with a safety guard embodying the present invention; f Y

' Figure 2 is a view inY transverse vertical section taken on line 2-2 of Figure 1, parts being shown in-elevation for the sake of simplicity in illustration;

Figure 3 is a'fragmentary detail 'view in top plan showing the mounting employed 4for one of the guide rods for the safety gate `and associated parts; f

Figure 45 is a fragmentary-'view in. front 929. Serial No. 360,071.

elevation showing a portion of one end of the safety gate andthe mounting and guiding means therefor; v

yFigure 5 is an enlarged fragmentary view in elevation showing one of the guides for the gate and associated parts; Y

Figure y6y is a view in horizontal section on line6-6 of Figure 5, the cotter pin being removedgfand ,f 'y `Fioure 7v is a view in vertical section on line aZ- of Figure 5, the cotter pin being shown in elevation.l

Referring to the drawings and more particularly to Figures 1 and 2,v a conventional toggle punch press is designated generally at 1 and has the usual frame 2 supporting a die 3. On the upper portionvof the frame 2 the conventional toggle mechanism 4 is provided and operates as usual Ato raise and lowerv the blank'holder 5. The punch 6 is -reciprocatediwithin the blank holder in the usual manner. Punch presses of this character are well known 'and widely used and need no detailed description. For the purposes of the present invention it is ksulicient to understand that when the blank holder 5 and punch 6.are elevated the operator places la blank of metal over the die 3 and then the blank holder tdescends to hold the blank in position 'and finally thepunch travels down through thef'blank holder and coacts with the die3 to suitably shape the blank, When theblank has been suitably shaped the blank holder and die are elevated and the operator thenf removes the properly shaped'blank and replaces it with anotherfflat blank. At times nthe operator does not remove his hand `in time to prevent its being caughtby the blank holder or punch and as a result the yhand is crushed.

In carrying out. the present invention a pair zof Xed guide rods 10 are provided,

there beingone guide rod at each side of the press. Each guide rod has its lower end secured bynuts 11 to a bracket 12, the brackety 12 being fastened to the frame 2 by one of the vstuds 13 that secures the frame to its vbase. The upper end of each guide rod passes through an apertured lug 14 providedk Onanangle bracket 15 secured to the ENT-OFFICE- frame of the press by a stud bolt 16. A nut 17 is threaded on the upper end of each guide rod and engages the lug 14 of its bracket.

A safety gate 20 is provided and has a substantially rectangular frame 21 to which a body of wire mesh fabric 22 is secured. Sliding guides, designated generally at 25, are provided for mounting the gate on the Guide rods 10 for vertical sliding, movement. 'referably, there are four such guides 25,. two at each end of the gate. The guides 25 are all of identical construction and. each consists of a pair of plates 26 and 27 hingedly connected at one end as at 28. Curved portions 29 on the plates 26 and 27 coact when the plates are brought together to provide a sleeveelike guide which slidably embraces the guide rod 10. The ends of the plates 26 and 27 remote from the hinge 28 are also provided with complementary curved portions 30 which coact to provide a clamp for securing the guide to the adjacent end rail 20 of the frame 2l of the sliding gate'. The curved portions 30 have corrugations or kcrimps 31 therein and are appropriately slotted as at 32 so that these curved portions 30 not only clamp the end rails of the gate but embrace and snugly lit the strands of the wire fabricand gate. One of the plates of each guide, preferably the plate 27 is welded to the gate.- `For the purpose of releasably securing theplates 26 and 27 together wherethe guide portions 2S) constitute a sleevelke guide slidably embracing their guide rod 16 and the clamping portions 30 are rigidly interconnected with the frame ofthe gate, `the plate 26 has vapertumd-lugs 433 struck therefrom and the plate 27 has slots 34 formed therein through which the lugs 33 project whenV the plates 26 und A27 are brought together. A cotter pin 35 is then inserted throughthe apertures of the lug 37, as shown in Figures 5 and 7, thereby holding the plates 26n and 27 together.

The weight of the gate 2O biases it to move `downwardly along the guide rods 10 tothe position shown' in Figure 1 and if the weight of the frame and wire mesh of the gate is 4not suflicient for this purpose an additional weight 40 may be secured to the lower rail of the frame. `For the purpose of lifting` the vgate up and controlling the lowering movement thereof, crank arms 41- are secured as by stud bolts 42 to the upper arms of the toggle mechanism 4 that operates the blank holder 5. The outer ends of these arms 4l project beyond thearins 4 otr the toggle mechanism `and `are bent over as shown in Figure 1 to aline their outer ends with the upper sliding guides ofthe gate. Flexible connections suchas chains 43 are provided and each has one end connected to the outer end of an arm 4l and its other end detachably connected 'to the overlying upper sliding grido The detachable connection between the lower end of the iieXible element 43 and its guide 25 may consist merely of a hook 44 carried by the lower end of the flexible element 43 and engaging in one of a series of openings 45 provided in the guides 25. Intermediate its ends each flexible element 43 is trained over a guide pulley 46 which is rotatably supported as at 47 on the bracket 15. .f

In operation, when the blank holder 5 and punch 6 are in raised positiontheA gate 20 is also in raised position because the arms 41 are then in the dotted line position shown in Figure 2. The operator then puts a blankl onto the die 3 beneath the blank holder and punch and '4 if the machine is running then the blank holder and punch descend,- but the gatealso descends in advance of the blank holder and punch because of the additional throw of the crank arms' 41. Thus, if the operator'were to be slow in removing his hand from beneath the blank holder and punch it would be struck by the gate 20 which would warn him and tend to displace his hand from beneath the blank vholder' and punch. Vhen the blank holder and punch are raised the gate20 is also raised due to the upward movement of the crank arms 41.

The sliding guides 25 which are provided serve not only to constrain the gate 20 to vertical sliding movement but also to permit `the 'gate to be swung around to one side of Ithepress to facilitate tool setting. To swing the gate in the manner described the cotter pin 35 associated with the guides at one side of the gate is removed from its lugs 33. Loss of the cotter pin is prevented by virtue of the provision of chains 49 which connect these Cotter pins to the wire mesh body of the gate.

-With one of the cotter pins 35 removed, the

plates 26 of the guides at one side may be swung about their hinges 28 thereby releasing the movable `guides from the guide rod 10 at one side of the press. When the guides at one side are disengaged from their fixed guide rod 10, they are supported on the gate due to the welding of the plates 27 to the gate. Prior to this the chains 43 are discon- 'nectedv from the upper guides 25. `When the gate is thus'disconnected from the ne Vible elements 43 and from one of the guide rods 10 it is supported in elevated position on the other guiderod by means of a Cotter pin 50 also carried onV the gate by means of a chain 51 and insertible through a transverse opening provided in the guide rod. The gate is thus supported elevated when it is swung out of the way because in its lowermost position it might interfere with convenient access to the tools.

` The invention claimed is:

\ 1. A safety device for use on punch presses of the type includinga die, a blank holder and a punch and a toggle operating mechanism therefor and comprising a traveling gate disvzo posed in front of the die, blank holder and pimch, means for constraining the gate to vertical sliding movement, means actuated by the operating mechanism of the press for constraining the gate to movement downwardly in advance of the blank holder and comprising crank arms connected to the arms of the toggle mechanism of the press and having a greater throw than the arms of the toggle to which they are connected, and nexible connections between said crank arm and said sliding gate.

2. A safety device for use on punch presses and comprising vertical guide rods supported upon the press, a gate, movable guides secured to the gate and slidably embracing the guide rods, and means connected to said movable guide for raising the gate up and down as the press is operated, at least certain of said guides comprising a pair of plates hinged together and having coacting portions providing a sleeve-like guide adapted to slidably embrace the guide rod, said plates also having portions adapted to be secured to the gate.

3. A safety device of the character described including fixed vertical guides, a gate, and sliding guides fixed to the gate and slidably embracing said fixed guides, at least certain of said sliding guides comprising a pair of plates hingedly connected at one end and having cooperable curved portions adapted to constitute a sleeve-like guide structure which slidably embraces the associated fixed guide, said plates also having cooperat- V ing curved portions adapted to be secured to the gate, and means for Vreleasably securingy the plates together and means for moving the Gate.

C 4. A safety device of the character described including fixed vertical guides, a gate, and sliding guides fixed to the gate and slidably embracing said fixed guides, at least certain of said sliding guides comprising a pair of plates hingedly connected at one end and having cooperable curved portions adapted to constitute a sleeve-like guide structure which slidably embraces the associated fixed guide, said plates also having cooperating curved portions adapted to be secured to the gate,

means for releasably securing the plates together, means for moving the gate, and means for supporting the gate in elevated position on one of the fixed guides when it is released from the other guide whereby to facilitate tool setting and the like.

5. A safety device for use on punch presses and including fixed guides, a traveling gate, sliding guides fixed to the gate and slidably embracing said fixed guides, means provided for synchronized movement of the gate as the press isV operated, at least certain of said sliding guides being made up of releasably connected elements which embrace their associated fixed guide whereby they may be disenelements which embrace their associated fixed guide whereby they may be disengaged from I their fixed guide.

7 A safety device for use on punch presses and comprising a traveling gate disposed in front of the press, means for constraining the gate to vertical sliding movement, means providing movement of the gate downwardly in advance of the operation of the press, and releasable means for supporting the gate in elevated position.

In witness whereof, I heretoaffix my signature.

FREDERICK I-I. KUNKEL. 

